Vulcan particle weapon

A Vulcan particle weapon was a type of weapon used by Vulcans in the mid-20th century. The dispersion of the weapon's energy could be adjusted, making it able to encompass and destroy thick walls of stone. Aboard a Vulcan survey ship, at least one particle weapon was stored in an armory case.

On Earth in 1957, Mestral sought a Vulcan particle weapon inside the wreckage of his ship in order to free a group of twelve Humanminers who had become trapped when a mine collapsed. The Vulcans planned to carefully hide the weapon from the Humans, fearing cultural contamination otherwise. In response to Mestral appealing to Vulcan shipmates T'Mir and Stron for help in finding the particle weapon, Stron refused but T'Mir eventually assisted Mestral. (ENT: "Carbon Creek")

It isn't entirely clear, from the episode, whether a tool Mestral thereafter uses, in the mine, to shoot a blue-colored beam of energy at a stratum of quartz, blasting away the rock, was intended to be the particle weapon he is shown searching for in the previous scene. This intent was, however, confirmed by the final draft script of "Carbon Creek", which also stated, "It's approximately the size of a Starfleet phase-pistol."